This study explores the antibacterial potential of a novel series of sulfamate-containing adamantyl carboxamides against multidrug-resistant (MDR) clinical isolates. A newly synthesized panel of these compounds was tested against both Gram-positive and Gram-negative MDR pathogens. Bactericidal assays demonstrated that compound 3 showed the highest activity against Streptococcus pneumoniae, achieving 70% bacterial reduction, while compound 1 completely eradicated S. pyogenes and Bacillus cereus. Notable bactericidal effects were also observed against Serratia marcescens, Escherichia coli K1, and Salmonella enterica, with compound 7 eliminating S. marcescens. MIC₅₀ analysis confirmed the potent antibacterial properties of these compounds, especially compound 7. Cytotoxicity was evaluated using lactate dehydrogenase (LDH) release assays in human brain microvascular endothelial cells (HBEC-5i), revealing low toxicity for most compounds; compounds 2, 3, 4, and 7 induced less than 20% cell death, while compound 1 showed moderate cytotoxicity (32%). These findings highlight the strong antibacterial efficacy and favorable safety profile of these novel compounds, supporting their potential as promising lead candidates for the development of new therapies targeting MDR bacterial infections

Balsam Qubais Saeed has completed her BSC in Biology in 1999 and her MSc Degree in Bacteriology in 2001 from University of Mosul, she got her PhD Degree, in Medical Parasitology from Tikrit University in 2006. postgraduate programs. She taught many courses in the Human Biology and Clinical Microbiology, she was a coordinator of PhD course of Molecular Medicine program of MBBS program, She has published more than 35 research articles in peer reviewed international journals, most of them in Q1 and Q2 journals, she is a reviewer for many international journals.